Two-cycle crankcase compression engine



1952 L. A. SUHADOLNIK ET AL 2,607,329

I TWO-CYCLE CRANKCASE COMPRESSION ENGINE Filed Dec. 15, 1949 sSheets-Sheet 1 5 IN VEN TORS AAWPWOF AszmooLu/k & HA??? 6. SANGEE g- 19,1952 L. A. SUHADOLNI K ET AL 0 TWO-CYCLE CRANKCASE COMPRESSION ENGINEFilgd Dec. 15, 1949 :5 Sheets-Sheet 2 19, 1952 L. A. SUHADOLNlK ET AL2,607,329

TWO-CYCLE CRANKCASE COMPRESSION ENGINE Filed Dec. 13, 1949 3Sheets-Sheet 5 INVENTORS A Awemce A. Sub A06! IV/k & H wey a. JA NGEEfly A TOE/v06 Patented Aug. 19, 1952 TWO-CYCLE CRANKCASE COMPRESSIONENGINE Lawrence A. Suhadolnik. Shaker. Heights, and

I Harry G. Sanger, Euclid, hio

Application December 13, 1949, Serial No. 132,755

This invention relates broadly to internal combustions and morespecifically to improvements in the organization and structure of thevalves, the operating mechanism therefor, and the construction of thecrankshaft.

One of the objects of the invention resides in the provision of a pairof fuel inlet valves arranged for operation by a single cam.

Another object of the invention is to provide a composite crank and camshaft and'improved journal bearings therefor.

Another object of the invention is to provide a crankcase having alimited volumetric capacity and a carburetor inlet valve to meter thefuel charge.

Another object of the invention is to provide a crankshaft structureembodying, a pair of aligned subassemblies which are designed forremoval from either side of the engine.

Further objects of the invention reside in the provision of arelativelysmall engine which-is light in weight, eflicient of operation,and constructed to facilitate simple machining operationsand readyassembly.

Other objects and advantages, more or less ancillary to the foregoing,and the manner in which all the various objects are realized,will appearin the following description, which, considered in connection with theaccompanying drawings, sets forth the preferred embodiment of theinvention.

In the drawings:

Fig. 1 is a vertical sectional view of the improved engine;

Fig. 2 is a vertical section of the engine taken on a plane indicated bythe lines 22 in Fig. .1;

Fig. 3 is a vertical section of the engine taken on a plane indicated bythe line 32-3 in Fig.1 with the piston shown in its elevated position;

and

Figs. 4 to 8 are diagrammatic views illustrating the operative cycle ofthe engine.

Referring first to Fig. 1, the engine comprises a combined cylinderblock and crankcase I!) having a boss in-the base thereof constituting acarburetor companion flange for the reception of a valve cage H, acylinder I2 having a'piston' l3 and inlet valve hi therein, and acylinder head l5 embodying the combustion chamber l6 and spark plug H.The crankcase is bored for the reception of bearing blocks IB'and 19,which in turn are bored for the support of the crankshaft bearings 20,and crankcase packing glands -2| The bearing blocks areformedwithflanged end portions 22 drilled for the reception of cap 11 Claims. (01.123-73) screws 23 mounted on faced areas 24 in. the op.- posed sides ofthe crankcase; 1

The crankshaft embodies two separable sections 25 and 26 disposed incoaxial ali nment with each other and interconnected through thetelescopic engagement of a pintle 21 on the crank arm 28-with a boreintheend of a boss 29 in the crank armgw. The boss forms the journalbear.-

ing for the connecting rod 3| and the bore therein'is slightly largerthan the pintle and provided with a snap ring F constituting a fulcrumto permit oscillation of the crank section 26in the event ofmisalignment of the crankshaft journal bearings. Thevcrank arms areofannular form,. disposed in close: proximity with the end Walls of thebearing blocks l8 and I9 and'the central body of the connecting rod 3i.The'opposed faces of :the crank arms are formed with recesses-therein toaccommodate the hub of the journal bearing ,theconnecting rod; Theqcranksection '25 isiprovidedwitha cam 32 formed integral therewith anddisposed betweena crankcase fuelvalve 33 and the cylinder valve M in aplane common to the axes thereof. 5

The cam, as will be seen in Fig. 2; is engaged with shoes 35 guided in:radial openings machined in the bearing block I8 intermediate. thebearings 20. The block i8 is furthermachined with an annular groove 36in the circumferential wall thereof, the flange 31 defined by the groovebeing provided with a plurality of openings forming transversepassageways .38 for the admissionof the fuel mixture from the valve 33to the crankcase.

The valve cage l l includes a plate 39 boredlfor the reception of aspider 4B for guiding the stem of the valve 33 and chamfered toform aseat for the head thereof. The cage further includes an elbow M-flangedfor-engagementwith the plate39 and cored to receivethe-valvezheadand a spring 42 for urging thevalve against its seat and for maintainingthe shoe 35 in contact with the cam. The'elbow is provided with a post43 disposed in axial alignment with the stem of the valve and formedwith a boss thereon for the support of the spring 42. The outer end ofthe elbow is provided in the customary mannerwith a flange for thesupport of the carburetor 44. The valve 33 is disposed approximately 45from the medial axisof'the valve M, which, as illustrated in Fig. 1, isparallel to theaxis of the cylinder 13. and normal to the axis of thecrankshaft section 25. The head of the valve 14 is seated in a sleeve 46mounted in a counterbore in a chamber 41 communicating with the groovethe cylinder head in super-tangential relation with the valve in a planecommon to the axes of the valve and cylinder. 7

The connecting rod 3| is mounted on needle bearings 53 on the boss 29,the upperend there- 7 of being connected in a similarmarmefto-arwfist5-and-the-depressionin the crankcase will effect the pin 54 in thepiston 55. The cylinderis prferably provided with alever:56,-;='which,';tggether with the cylinder block, is cross-drilledin the central portion thereof to provide exhaust-ports 51 tangentialthe upperface of the piston when -disposed-in"itsrlowersdeaidzcenten:position.

The outer end of theecrankshaft' 25 is=zprovided with ea fiywheel 2'58:zkeyed izthereon and :locked agains ateral movementibyzarnut 59.iArpacking 'gland-E 2 l isdisposedzbetweemthe inner face:of.-;the

flywheelrand thelendzwall.oiithexcrankshaftirbear- 'ingLblock-am.iThesouter: endaaofiatheashaft' 2521s diametricallyfreducediforcthezsupportrofrasmag- -netoii60 .;of conventionalr-form-:which isr mounted on a qnlateiifi l' piloted ioniaiishouldervinithezbearing: block M 9 :and i-retaine'd :tthereon :byra :snap ring fiz.

'zfIhe: .crankshaftebearineszznzcompriser ningsztfit having annularzgroovesit B4: thereinzadjacent :Lthe outer: ends thereof. I-hecbore, inthe'ring iSZIJXEO- wided-mith rollers fi5 tormed'iwith diametricallyreduced eridportionstiifizwhichzaare engaged-smith 2a; split-ring 6 hotright:-angular:transversezsection. In assembly, the: inner i flanges of:the ':-'rings sa-re seatedi-in thergroovesxM-iand' the outeri'flanges414 descent 0f the piston, the ffuel r charge :in :ithe

crankcase will be compressed and'-f'fiow:,through the'passageways'38-':and into theichamber 47!. iBefore' the -pistonreaches'bottomideadcenteniabout of the descent 'thereo'f) the cam willopen" the walve I 4 fEigf 5) iarrdzthe" fuelccharge willaenter sthe:combustion chamber it. :When Etherpiston rreachessbottomrdead; centeriFigzfG) 'the cam -will ibe int-'itsLposition-ofzmaxinmm lift; butcontinued movementi thereofrwi'll effect::the.:closure:ofzthe valve as,the: crankshaftr pass esaa: point; 31b0l1t545 7 0 fbeyondcbottom;deadscenter during. theselevation oftzthe piston .(Eig: :7 rC'ontinuedymovement'of vthe :piston wi-ll.compresslthe'fuel.chargeentrapped :within:theccombustionxchamber:runtil: the :crankarmrreachessawpointapproximately 15: forward 7 5 4 top dead centerwhereupon the ignition system will fire the compressed fuel charge andcause the expansion thereof. As the crank pin passes top dead center,the expanded gases will effect the descent of the piston until itreaches its lowermost position and liberates the burned products ofcombustion through the exhaust ports 51.

Before vrtheer'ii'ston reaches bottom idead center, the-"ca-mwill "openthe valve ['4 Fig."-5)-*and permit a portion of the compressed fuelcharge in *the crankcase and chamber 47 to flow into thezcyli-r-ider-v-andrthusscavage the contents thereof.

: During the last quadrant of the ascent of the piston (Fig. 8) the camwill actuate the valve 33 "admission-of the fuel mixture from thecarburetor :inlzmthemrankcase. Continued rotation of the crank and camwill close the valve 33 coincident "the' passage of the crank arm beyondtop dead center (Fig. 4).

Althoug-h :the foregoing :description is .:necessarily ofwaidetailedrcharacter yin-order .thatartheinvention:zmaycbezcompletely,set% forth,-.-it is to ,be understood'zthatzithe, specific gtermi-no'logy is not intended to berestrictive:or-rconfining, and: that various :rearrangements :of gpartsand modifications'of detail mayzberesortedtmwithoutdeparting fromthesscope :orr. spirit- 0f? the invention as ':herein-'claimed.

'Weiclaim:

1. An internal combustion-aengine-:comprisingsa crankcase, a. cylinderblock thereon hav-ingra iuel 'chambertthereingagcylinder head- -on .said.;block having-a 'cumbustion: chamber therein,-.;an intake poppet valvein said fuel chamber adjacentesazid combustion chambena carburetorronsaidscrankcase,- a,;carburetorspoppetsualvein saidzcrankcase subjacentsaidfuel: chambeniima: plane; common to that ofsaidfintakeiya'lvesazcrankshaftimsaid crankcasesa connectingzrodthereoma; piston in sai'd:cyl-irrderzblockwoupledwith saideconnecting rodaicam: on= said: crankshafta disposed between and-rotatable :.:aboutithe epoint :of intersection-mi the axes of saidintakezandzcarburetor'valves, springs urging saidx valves into.operative engage 'mentlwith said cam, .saidwcrankcase ,havinggpas-:sageways atherein communicating with thescarburetonvfivexoperiing:the:crankcase and thefuel :chamber.

- 2.. *An internal :combustion a-engine comprisi-ng a crankcase, acylinder block thereon::having=;a fuel chamber therein, acylinderI-hea'deon said 'blockshaving Fa: combustion :chamber thereinganintake poppet valve in saidfuelcchamberradjacenirsaidnombustionchambena-careburetor'onsaidecrankcasemarcarburetor poppet valve insaid crankcasesub-iacentgsaid; fuel ;chamber; a: crank- .shaftiimsaid crankcase; aconnecting rod thereon, a :piston irrasaid; cylinder bIGCkTiCOllPlBdwith: said connecting rod, a cam on said crankshaft Idis-:posed-zbetween;andcoperativelmengaged withasaid intake andcarburetorwvalvesaiand 1a crankshaft .-bearingclrrlock:in:saidrzcrankcase*having' passageways :therein 3 connecting sthetcarburetor :valve qopeningnwithathe crankcase: and fuel chamber.

. 3.;An-.-internal combustion "engine comprising a crankcase: a cylinder:block thereon having .a fuelchamber .therein, wa cylinder head: on said:block havi-nsa combustion chamber therein, an -intake poppet =va1veins-said tfuel cchamber rad- ;iacent. :said combustionchamber, acarburetor on saidrcrankcase-a carburetor; poppet valve. in said:crankcase subjacent -.said 7 fuel chamber, .a :c-ranksha-ftin. ;saidcrankcase, a connecting; rod .thereon, :a; piston insaid--.'cylinder-.block: coupled with said connecting rod, acam on 'said'crankshaftdisposed with the peak thereof in axial alignment with the connectingrod bearing and remote therefrom, said cam being disposed between andoperatively engaged with said intake fuel chamber therein, a cylinderhead on said block having a combustion chamber therein, an

intake poppet valve in-said fuel chamber adjacent said combustionchamber, a carburetor on said crankcase, a carburetor poppet valve insaid crankcase subjacent said fuel chamber, a crankshaft in saidcrankcase, a connecting rod thereon, a piston in said cylinder blockcoupled with said connecting rod, a crankshaft bearing block in saidcrankcase valve, lifter shoes mounted for sliding movement in said blockand disposed in a common plane transverse the axes of the crankshaft, acam on said crankshaft engaged with said shoes, said bearing blockhaving recesses therein connecting the carburetor valve opening withsaid crankcase and said fuel chamber.

5. An internal combustion engine comprising a crankcase, a cylinderblock thereon having a.

fuel chamber therein, a cylinder head on said block having a combustionchamber therein, an intake poppet valve in said fuel chamber adjacentsaid combustion chamber, a carburetor on said crankcase, a carburetorpoppet valve in said crankcase subjacent said fuel chamber, a crankshaftin said crankcase, a connecting rod thereon, a piston in said cylinderblock coupled with said connecting rod, a crankshaft bearing block insaid crankcase having a circumferential groove therein aligned with saidfuel chamber, a transverse opening leading from the groove to thechamber defined by the crankcase, valve lifter shoes in said block belowsaid groove engaged with said inlet and carburetor valves, a cam on saidcrankshaft engaged with said shoes, and springs urging said shoes intoengagement with said cam.

6. An internal combustion engine comprising a crankcase, a cylinderblock thereon having a fuel chamber therein, a cylinder head on saidblock having a combustion chamber therein, an intake poppet valve insaid fuel chamber adjacent said combustion chamber, a carburetor on saidcrankcase, a carburetor'poppet valve in said crankcase subjacent saidfuel chamber, a crankshaft in said crankcase, a connecting rod thereon,a piston in said cylinder block coupled with said connecting rod, acrankshaft bearing block in said crankcase having recesses thereinconnecting with the carburetor valve opening, the interior of thecrankcase, and the fuel chamber, a crankshaft section in said bearingblock, a cam on the crankshaft intermediate said intake and carburetorpoppet valves and operatively engaged therein, a second crankshaftbearing block in said crankcase in axial alignment with the first-namedbearing block, a second crankshaft section journaled thereon, shoulderson said crankshaft sections restraining axial movement thereof, a flangeon the outer end of each of said bearing blocksdemountably connected tothe outer walls of said crankcase, whereby said bear- 6 ing blocks andthe crank sections thereon may be removed as units from the opposedsides of the crankcase. j

"7. An internal combustion engine comprising a c'r'ank case, a cylinderblock thereon having a 'fuel'cha'mber therein,'a cylinder head on saidblock having a combustion chamber therein, an intake poppet valve insaid fuelchamber adjacent said combustion chamber, a carburetor on saidcrankcase, a carburetor poppet valve in said crankcase subjacent saidfuel chambena crankshaft in said crankcase, a connecting rod thereon, apiston in said cylinder blockjc'oupled with'said connecting "rod, acrankshaft bearing block in said crankcase having re'cessesftl'iereinconnecting with the carburetor valve opening, the interior of'thecrankcase, and the fuelchamber, a

crankshaft section in-said bearing block, a cam on the'crankshaftintermediate said intake and carburetor poppet valves and operativelyengaged therein, a second crankshaft bearing block. in said crankcase inaxial alignment with the firstnamed bearing block, a second crankshaftsection the other crankshaft section slidably engaged.

with the opening in said boss, and detachable means on said bearingblocks for the retention thereof.

8. An internal combustion engine comprising a crankcase, a cylinderblock theeron having a fuel chamber therein, a cylinder head on saidblock having a combustion chamber therein, an intake poppet valve insaid fuel chamber adjacent said combustion chamber, a carburetor on saidcrankcase, a carburetor poppet valve in said crankcase subjacent saidfuel chamber, a crankshaft in said crankcase, a connecting rod thereon,a piston in said cylinder block coupled with said connecting rod, acrankshaft bearing block in said crankcase having recesses thereinconnecting with the carburetor valve opening, the interior of thecrankcase, and thefuel chamber, a crankshaft section in said bearingblock, a cam on the crankshaft intermediate said intake and carburetorpoppetvalves and operatively engaged therein, a second crankshaftbearing block in said crankcase in axial alignment with the first-namedbearing block, a second crankshaft section journaled thereon, shoulderson said crankshaft sections restraining axial movement thereof, andantifriction bearings in said bearing blocks comprising cylindricalraces having internal grooves adjacent the outer ends thereof, rollersin said races, pins protruding from the opposed ends of said rollers,and snap rings of right angle cross section engaged in said grooves andwith said pins.

9. An internal combustion engine comprising a crankcase having acarburetor passageway therein, a cylinder block thereon having a fuelpassageway therein communicating with the first-named passageway, acylinder head on said block having a combustion chamber therein, acrankshaft in said crankcase, a connecting rod thereon, a piston in saidcylinder block coupled with said connecting rod, a single lift cam onsaid crankshaft, a poppet valve in the cylinder block passagewaydisposed in radial alignment with the axesof said cam and operativelyengaged with the face thereof, and a poppet valve in the crankcasedisposed in radial alignment with the axes of

